In general, most users possess a plurality of electronic devices such as Smartphone and tablet PC, and the users may need to share a common file in the electronic devices, and the file contains data including photo, text, music or movie.
In addition, the users can install wireless and cable communication modules in the electronic devices for transmitting the file. Wherein, the cable communication transmission module is used as an example for illustration, and the cable communication module generally comes with a female connector, so that a user must have a transmission line with an additional male connector before the user can transmit the file between two electronic devices.
However, the conventional transmission line is simply provided for transmitting data (or electric power) between the electronic devices only. The user may want to have a multifunctional transmission line (such that the transmission line has the functions of a flash memory for storing data or a card reader for reading a memory card), and the multifunctional transmission line not only enhances the applicability and efficiency of the transmission line, but also overcomes the problem of carrying the flash memory or the card reader inconveniently.